<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			* {
				list-style: none;
				padding: 0px;
				margin: 0px;
			}
			
			.li1+li {
				color: #f00;
			}
			
			.li2~li {
				color: #f00;
			}
		</style>
	</head>
	<body>
		<ul>
			<li>1</li>
			<li>2</li>
			<li class="li1">3（我）</li>
			<li>4</li>
			<li>5</li>
		</ul>
		<hr>
		<ul>
			<li>1</li>
			<li>2</li>
			<li class="li2">3（我）</li>
			<li>4</li>
			<li>5</li>
		</ul>
	</body>
</html>